An ethylene-propylene copolymer (EPR) was functionalized in the melt by grafting with itaconic acid and its mono- and di-methyl esters by using dicumyl peroxide as radical initiator. Grafting reactions were carried out in a Brabender-Plasticorder at 180 degrees C under a nitrogen flow at a speed of 75 rpm for 6 min. Fourier transform infrared spectroscopy (FTIR) was used to confirm the existence of grafted monomers. The absorption bands characteristic of each monomer grafted were observed in the FTIR spectrum of the modified EPR and were taken as evidence of grafting. The percentage of grafting attained was also followed by FTIR analysis, where the amount of monomer incorporated in EPR was estimated from a calibration curve established for the monomers used in this work. The degree of grafting obtained was 1.1% by weight of EPR for itaconic acid, 1.2% for monomethyl itaconate and 2.5% for dimethyl itaconate. Rheological and contact angle measurements indicate that the polarity of EPR is increased by grafting reaction. (C) 2005 Elsevier B.V. All rights reserved.